1. 08 Aug, 2016 1 commit
  2. 05 Aug, 2016 1 commit
    • Robbert Krebbers's avatar
      Iris 3.0: invariants and weakest preconditions encoded in the logic. · 1f589858
      Robbert Krebbers authored
      This commit features:
      
      - A simpler model. The recursive domain equation no longer involves a triple
        containing invariants, physical state and ghost state, but just ghost state.
        Invariants and physical state are encoded using (higher-order) ghost state.
      
      - (Primitive) view shifts are formalized in the logic and all properties about
        it are proven in the logic instead of the model. Instead, the core logic
        features only a notion of raw view shifts which internalizing performing frame
        preserving updates.
      
      - A better behaved notion of mask changing view shifts. In particular, we no
        longer have side-conditions on transitivity of view shifts, and we have a
        rule for introduction of mask changing view shifts |={E1,E2}=> P with
        E2 ⊆ E1 which allows to postpone performing a view shift.
      
      - The weakest precondition connective is formalized in the logic using Banach's
        fixpoint. All properties about the connective are proven in the logic instead
        of directly in the model.
      
      - Adequacy is proven in the logic and uses a primitive form of adequacy for
        uPred that only involves raw views shifts and laters.
      
      Some remarks:
      
      - I have removed binary view shifts. I did not see a way to describe all rules
        of the new mask changing view shifts using those.
      - There is no longer the need for the notion of "frame shifting assertions" and
        these are thus removed. The rules for Hoare triples are thus also stated in
        terms of primitive view shifts.
      
      TODO:
      
      - Maybe rename primitive view shift into something more sensible
      - Figure out a way to deal with closed proofs (see the commented out stuff in
        tests/heap_lang and tests/barrier_client).
      1f589858
  3. 27 Jun, 2016 1 commit
    • Robbert Krebbers's avatar
      Rename type classes in proof mode. · 1aae01e6
      Robbert Krebbers authored
      We are now using the prefixes Into, From, and Is (the first two are
      inspired by the names of some traits in the Rust stdlib), and hopefully
      doing that consistenly.
      1aae01e6
  4. 23 Jun, 2016 1 commit
  5. 03 May, 2016 1 commit
  6. 20 Apr, 2016 1 commit
    • Robbert Krebbers's avatar
      Improve iFrame tactic · 43d45c6b
      Robbert Krebbers authored
      - It can now also frame under later.
      - Better treatment of evars, it now won't end up in loops whenever the goal
        involves sub-formulas ?P and it trying to apply all framing rules eagerly.
      - It no longer delta expands while framing.
      - Better clean up of True sub-formulas after a successful frame. For example,
        framing "P" in "▷ ▷ P ★ Q" yields just "Q" instead of "▷ True ★ Q" or so.
      43d45c6b
  7. 19 Apr, 2016 1 commit
  8. 11 Apr, 2016 1 commit